Korsakoff's syndrome

Korsakoff's syndrome (Korsakoff's psychosis, amnesic-confabulatory syndrome), is a degenerative brain disorder caused by the lack of thiamine (vitamin B₁) in the brain. The syndrome is named after Sergei Korsakoff, the neuropsychiatrist who popularized the theory.

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Symptoms

There are six major symptoms of Korsakoff's syndrome: anterograde and retrograde amnesia, or severe memory loss; confabulation, that is, invented memories which are then taken as true due to gaps in memory sometimes associated with blackouts; meager content in conversation; lack of insight, and apathy (the patients lose interest in things quickly and generally appear indifferent to change).

These symptoms are caused by a deficiency of thiamine (vitamin B₁), which is thought to cause damage to the medial thalamus and possibly to the mammillary bodies of the hypothalamus as well as generalized cerebral atrophy.^[1]

When Wernicke's encephalopathy accompanies Korsakoff's syndrome, the combination is called the Wernicke-Korsakoff syndrome. Korsakoff's is a continuum of Wernicke's encephalopathy, though a recognised episode of Wernicke's is not always obvious.

Korsakoff's involves neuronal loss, that is, damage to neurons; gliosis which is a result of damage to supporting cells of the central nervous system; and hemorrhage or bleeding in mammillary bodies. Damage to the dorsomedial nucleus of the thalamus is also associated with this disorder.

Signs

• Ataxia
• Apathy
• Retrograde amnesia and anterograde amnesia
• Confabulation (inventing events to compensate for gaps in memory)
• Tremors
• Paralysis of muscles controlling the eye
• Lack of insight to the condition
• Coma

Treatment

Treatment involves replacing the thiamine by intravenous (IV) or intramuscular (IM) injection, and providing proper nutrition and hydration. However, the amnesia and brain damage caused by the disease does not respond to thiamine replacement therapy. In some cases, drug therapy is recommended to the patient. If treatment is successful, signs will show within two years though recovery is slow and often incomplete.

Causes

Conditions resulting in the vitamin deficiency and its effects include chronic alcoholism, and severe malnutrition. Alcoholism is often an indicator of poor nutrition, which in addition to inflammation of the stomach lining, causes thiamine deficiency.^[2] As well as alcohol abuse, causes include dietary deficiencies, prolonged vomiting, eating disorders, or the effects of chemotherapy. It can also occur in pregnant women who have a form of extreme morning sickness known as hyperemesis gravidarum.^[3] Mercury poisoning can also cause it. It also been caused by centipede (mukade) bites in Japan^[4].

Due to malnutrition and a lack of Thiamine, the hippocampus begins to decay, leaving holes that disallows one's rehearsed information within short term memory to transfer to long term memory (anterograde amnesia)

Prevention

The most effective method of preventing Korsakott's syndrome is to avoid B vitamin/thiamine deficiency. In Western nations the most common cause of such deficiency is alcholism, so almost all new cases of Korsakoff's could be avoided by governmental requirements to add trace amounts of B vitamin to all alcohol sold. In the U.S., this approach has been blocked by political groups asserting that such supplementation would encourage alcohol use.

Case studies

A famous case study is recounted by Oliver Sacks in "The Lost Mariner", which can be found in The Man Who Mistook His Wife for a Hat.

Another case is that of the Australian artist Charles Blackman.^[5]

In popular culture

• In the fictional show House, episode "Histories", the clinic patient suffers from Korsakoff's as a result of malnutrition.
• In the novel Mona Lisa Overdrive, the character Slick was incarcerated in a "chemo-penal unit" with "induced Korsakov's" (sic).

References